Polyethylene strip treating machine



May 3, 1966 J. R. PAULSON POLYETHYLENE STRIP TREATING MACHINE 2 Sheets-Sheet 1 Filed Aug. 5, 1963 INVENTOR JOHN R. PAUL SON PATET AGE N T y 1966 J. R. PAULSON 3,249,086

POLYE'IHYLENE STRIP TREATING MACHINE Filed Aug. 5, 1963 2 Sheets-Sheet 2 a I INVENTOR Q Jami A. P404 6011/ we? 20M,

PATENT AGENT 3,242,086 POLYETHYLENE STRIP TREATENG MACHINE John R. Paulson, Lachnte, Quebec, Canada, assignor to Paulson Machine Company Limited, Lachnte, Quebec, Canada Filed Aug. 5, 1963, Ser. No. 299,717 3 Qlaims. (Cl. 118-6) This invention relates to a polyethylene strip treating machine.

It is frequently desirable to adhesively apply a polyethylene strip to articles and objects of various kinds. For instance, such strips may be applied to envelopes, bags, and carton wrappers to serve as opening tear strip-s. While the application of an adhesively coated strip to such articles is not a problem if applied manually, it does constitute a problem when such a strip is applied to a massproduced quantity of objects in such a manner that it does not interrupt or slow up the mass-produced objects as they move along a production line. In such a case, the feeding of a pre-coated adhesive strip from a supply reel is not economically feasible because such a continuous adhesivecoated strip will not move oh. a supply reel at sufficient speed. Moreover, it is highly desirable that the cost of applying and drying the adhesive coating on the strip be kept to a minimum.

Furthermore, a polyethylene strip is subject to stretching during treatment and such stretching interferes with the desirable constant speed of delivery.

It is an object of this invention to provide a polyethylene strip treating machine which is adapted to apply an adhesive coating to a continuous strip fed from a supply reel of uncoated strip, which incorporates a drying rack for adhesively-coated strip, which delivers the strip in continuous adhesive-coated form, and which includes means for ensuring delivery of the strip at a substantially constant speed.

In accordance with the invention, therefore, a machine is provided which includes means for withdrawing a continuous strip from a supply reel, means for compensating for slackness which may occur in the withdrawn strip as a result of stretching or the like, means for applying an adhesive coating to one surface of the strip, a drying rack providing a period of drying for the coating, and finally a further means for taking up any subsequent slackness that may occur in the treated strip whereby the latter is delivered by the machine at substantially constant speed.

The invention will be described with reference to the accompanying drawings, in which FIGURE 1 is a side elevation of a machine in accordance with the invention,

FIGURE 2 is an end elevation of a portion of the machine,

FIGURE 3 is an end elevation of another portion of the machine,

FIGURE 4 is a plan view, and

FIGURE 5 is a perspective view of a detail of a slack take-up device.

The machine is shown as mounted on a base plate 228 and comprises a frame 229 mounted on legs 230. A reel 231 contains a supply of strip material 114 As previously indicated such strip material is ordinarily of polyethylene composition.

The reel 231 has its spindle 232 supported in notched arms 233 carried by the frame. The strip is paid out from the reel by means of a friction roll 234 which rests on the strip roll and which is fixed to a shaft 235 journalled in a frame member 236. Shaft 235 is driven by means of a sprocket 237 fixed thereto, a chain 238, and a sprocket 239 fixed to a driven shaft 240 journalled in main frame 229. Frame member 236 is pivoted by means of collar United States Patent 0 M 3,249,036 Patented May 3, 1966 241 to shaft 240. A chain tightening sprocket 242 may be provided. It will thus be apparent that the weight of roll 234 and the adjoining end of the frame member will be borne by the reel and that rotation of roll 234 in acounterclockwise direction (as viewed in FIGURE 1) will rotate the reel in a clockwise direction to pay out strip therefrom.

The strip is led initially in an upwardly inclined direction over a pulley 243 suspended from the frame, and thence downwardly over a pulley 244. Pulley 244 is rotatably carried by a rod 245 reciprocally mounted in a bracket 24-6 fixed to a post 230 and urged in a downward direction by a spring 247 on the rod and engaging a shoulder 248 on the bracket and a shoulder 249 on the rod. The resiliently mounted pulley 244 is for the purpose of taking up any slack that may occur in the paid out strip as a result of variations in the length of the paid out strip caused by the varying positions on the reel from which the strip is withdrawn.

Further, in order to compensate and make necessary ajustments for any variations in speed of the paid out strip, which may result from various causes, including stretching of the strip, a strip accumulator 25% is provided. Such accumulator comprises an auxiliary frame 251 having an upper series of idler pulleys 252 rotatably mounted therein on a fixed axis provided by shaft 253. A second lower series of pulleys 254 in vertically opposed relation to pulleys 252 are also rotatably mounted in the frame on a shaft 255 which however has its ends disposed in vertical slots 256 whereby the series of pulleys 254 may float in a vertical direction. The strip 110 from pulley 244 is trained over the first pulley 254, then upwardly over a first pulley 252, then downwardly over the second pulley 254 and so on. A yoke 257 is carried by shaft 255 and should a break occur in the strip, the series of pulleys 254 will drop to the lower end of the slots 256 in which position the yoke will engage a depressible switch button 258 of a switch 259. The switch 259 is disposed in the main circuit 260 of the power supply for the machine and is adapted to interrupt such supply and stop the machine should a break in the tear strip occur.

Also carried by the shaft 255 is a bar 261 having an upper lateral projection 262 and a lower lateral projection 262 and a lower lateral projection 263. Mounted on frame 251 by means of a bracket 264 is a mercury switch 2 265 which is connected through a junction box 266 to a solenoid 267' having an actuating plunger 268. Should shaft 255 of pulleys 254 drop to a predetermined level as a result of slackness in the strip, projection 262 will actuate switch 265 to energize solenoid 267. When, however, such slackness is taken up and shaft 255 with pulleys 254 rise to a level where projection 263 engages switch 265, the latter will be actuated to dee-nergize the solenoid 267.

As shown in FIGURE 1, solenoid 267 is mounted on frame member 236 and plunger 268 is pivotally connected at 269 to an arm 270 which in turn is pivotally mounted at 271 to frame 236. Arm 270 has an inclined end portion 272 on which is mounted a cylindrical shoe 273 overlying the coil of strip on reel 231 and normally slightly spaced therefrom. When solenoid 267 is energized, plunger 268 moves upwardly to swing shoe 273 downwardly into engagement with the strip coil. By reason of the pivotal mounting of frame 236 and the elements carried thereby, pressure on the strip coil by shoe 273 will also swing the adjacent end of frame 236 slightly upwardly to disengage roll 234 from the strip coil. Shoe 273 will thus act as a brake to arrest or slow down the rotary movement of reel 231. As soon as the slack in the strip is taken up by the pulleys 252 and 254 and shaft 255 rises, the solenoid is de-energized by engagement of projection 263 with switch 265.

The strip now extends over an abrasive wheel 274 fixed to a driven shaft 275 journalled in the main frame. Wheel 274 lightly abrades the lower surface of strip 110 preparatory to application of adhesive thereto.

The strip is then led under an idler pulley 276 and thence upwardly over an adhesive-applying wheel 277 fixed to a shaft 278 driven by a sprocket 279. Wheel 277 depends into a bath 280 adapted to contain adhesive. Wheel 277 has a lightly pocked surface 281 to facilitate retention of a layer of adhesive thereon when it moves out of the bath. Means may be provided for accurately determining the thickness of the layer of adhesive on the peripheral surface 281 and, as shown, comprises a U-shaped plate 282 mounted on the top of the bath and having an edge 283 adjustably spaced from the surface 281. Adjustment of such spacing is effected by mounting the plate on the bath with screws 284 which extend through slots 285 in the plate. A screw 286 fixed to the plate with locknut 287 may be employed to adjust the position of the plate.

Following application of adhesive to the strip, it is necessary that the strip be subjected to a drying period before application to the envelopes or other articles. To this end, the strip is subjected to a relatively long path of travel. A plural-grooved pulley 288 is fixed to shaft 240 and a second plural-grooved pulley 289 is fixed t shaft 275 in opposed relation to pulley 288. The strip is directed by means of an idler pulley 290 into the first groove of pulley 289 and is then trained back and forth in the grooves of pulleys 288 and 289 whereby it requires a period of time, say to seconds, for th strip to traverse such pulleys.

Shafts 240 and 275 and sprocket 279 are driven by means of a sprocket 291 on shaft 240, sprocket 292 on shaft 275, chain 293, bevel gear 294 on shaft 275, bevel gear 295 on shaft 296, and a connecting drive with motor 297. A chain-tightening idler sprocket 298 may be provided.

As the strip moves from the last groove of pulley 289 it is directed through a second accumulator 299 where it is again subjected to a slack take-up and speed control. Accumulator 299 is similar in structure to accumulator 250 and includes a frame 300, an upper series of pulleys 301 on a fixed axis shaft 302, a lower series of pulleys 303 on a shaft 304 having vertical sliding movement in slots 305, a bar 306 fixed to shaft 304 having upper and lower switch actuating projections 307 and 308, and a mercury switch 309 mounted on bracket 310. In this case, however, switch 309 is in a circuit 311 of a magnetic clutch 312 interposed in driven shaft 275. The arrangement is such that when pulleys 303 drop to a predetermined level, switch 309 will be actuated to de-energize the clutch 312 and thus interrupt the drive until there is suflicient tension in the strip to raise the pulleys 303 and thus again actuate the switch to energize the clutch.

From the accumulator 299, the strip 110 is led in any suitable manner to its particular area of use.

While most of the elements of the machine described will be formed of metal, it is desirable that certain elements be of plastic composition. Such elements include the brake member 273, and the pulleys 252, 254, 288, 289,301 and 303. Such plastic composition is preferably of the type sold under the trade mark Teflon.

I claim:

1. A machine for applying an adhesive coating to a surface of a strip which comprises a frame, a strip supply reel rotatably mounted in said frame, an adhesive supply receiving bath mounted on said frame, an adhesive applying roll rotatably mounted in said frame and extending into said bath, means for driving said roll, guide rollers for directing strip onto said roll, and a drying rack comprising a first series of strip supporting pulleys rotatably mounted in said frame on a common axis, a second series of strip supporting pulleys rotatably mounted in said frame on a second common axis, means driving said supporting pulleys and a slack take-up and strip speed controlling device at each end of said drying rack, each said device comprising an auxiliary frame, a first series of pulleys rotatably mounted in said auxiliary frame about a fixed axis, a second series of pulleys rotatably mounted in said auxiliary frame about a floating axis, a switch actuatable in response to movement of said floating axis to a predetermined plane, electrical means energizable in response to actuation of one of said switches to arrest rotation of said reel, and electrical means energizable in response to actuation of the other of said switches to arrest rotation of said two series of supporting pulleys.

2. A machine for applying an adhesive coating to a surface of a strip which comprises a frame, a strip supply reel rotatably mounted in said frame, an adhesive supply receiving bath mounted on said frame, an adhesive applying roll rotatably mounted in said frame and extending into said bath, means for driving said roll, guide rollers for directing strip onto said roll and a drying rack comprising a first series of strip supporting pulleys r0- tatably mounted in said frame on a common axis, a second series of strip supporting pulleys rotatably mounted in said frame on a second common axis, means driving said supporting pulleys, and a slack take-up and strip speed controlling device at each end of said drying rack, each said device comprising an auxiliary frame, an upper series of pulleys rotatably mounted in said auxiliary frame about a fixed axis, a lower series of pulleys rotatably mounted in said auxiliary frame about a floating axis, said lower series having a shaft slidably movable in a vertical direction in said auxiliary frame, a switch actuating member carried by said shaft, and a switch actuatable by said member in response to vertical movement of said shaft, a braking member surmounting said reel, electrical means for actuating said braking member, one of said switches being actuatable to energize said electrical means in response to downward movement of one of said shafts and to de-energize said electrical means in response to upward movement of said one shaft, a magnetic clutch interposed in said driving means for said supporting pulleys of said rack, said other switch being actuatable to de-energize said magnetic clutch in response to downward movement of the other of said shafts and to energize said magnetic clutch in response to upward movement of said other shaft.

3. A machine for applying an adhesive coating to a surface of a strip as defined in claim 2, including an electrical power supply circuit therefor, a third switch mounted in said auxiliary frame below said one shaft and disposed in said circuit, said one shaft having a second switch actuating member depending therefrom and engageable with said third switch to interrupt said power supply circuit.

References Cited by the Examiner UNITED STATES PATENTS 1,267,080 5/ 1918 Judelshon 242- 1,663,232 3/ 1928 Ambler 118-6 2,673,546 3/1954 Newton 118--68 3,090,666 5/1963 Jones 68175 CHARLES A. WILLMUTH, Primary Examiner.

LEON G. MACHLIN, Assistant Ex'aminer. 

1. A MACHINE FOR APPLYING AN ADHESIVE COATING TO A SURFACE OF A STRIP WHICH COMPRISES A FRAME, A STRIP SUPPLY REEL ROTATABLY MOUNTED IN SAID FRAME, AN ADHESIVE SUPPLY RECEIVING BATH MOUNTED ON SAID FRAME, AN ADHESIVE APPLYING ROLL ROTATABLY MOUNTED IN SAID FRAME AND EXTENDING INTO SAID BATH, MEANS FOR DRIVING SAID ROLL, GUIDE ROLLERS FOR DIRECTING STRIP ONTO SAID ROLL, AND A DRYING RACK COMPRISING A FIRST SERIES OF STRIP SUPPORTING PULLEYS ROTATABLY MOUNTED IN SAID FRAME ON A COMMON AXIS, A SECOND SERIES OF STRIP SUPPORTING PULLEYS ROTATABLY MOUNTED IN SAID FRAME ON A SECOND COMMON AXIS, MEANS DRIVING SAID SUPPORTING PULLEYS AND A SLACK TAKE-UP AND STRIP SPEED CONTROLLING DEVISE AT EACH END OF SAID DRYING RACK, EACH 